Cationic metal-containing azo dyes from 8-hydroxyquinoline



United States Patent 3,399,186 CATIONIC METAL-CONTAINING AZO DYES FROM S-HYDROXYQUINOLINE Kenjiro Hosokawa, Osaka, Yasushi Kojima, Hirakata, and Motoo Mori and Masaaki Suzuki, Osaka, Japan, assignors to Kanegafuchi Spinning (30., Ltd., Tokyo, Japan No Drawing. Original application Jan. 17, 1963, Ser. No. 252,026. Divided and this application Aug. 16, 1965, Ser. No. 480,100

Claims priority, application Japan, Jan. 24, 1962, 37/2,670; Oct. 23, 1962, 37/47,467 8 Claims. (Cl. 260-148) ABSTRACT OF THE DISCLOSURE Water-soluble metal-containing cationic dyestuffs are made by reacting dyes having either COOH and OH groups in ortho position with respect to one another in the molecule or dyes having CHNOH and OH groups, similarly located, with from 1 to 4 moles per mole of starting dye, of a metal compound that has trior tetravalent titanium, or tetravalent zirconium, or, most importantly, trivalent chromium, and possesses a basicity lower than 33.3 percent, the reaction medium being an organic solvent that is a solvent for both the starting dye and the metallized dye product and is at least partially miscible wtih water, the pH of the reaction being below 4. The starting dyes disclosed are unsulfonated and are mostly monoazo though some disazo and triaryl-methane dyes are shown. The metallized dyestuffs are suitable for dyeing a large variety of substances using conventional methods since they are stable against thermal decomposition.

The present application is a division of copending application, Ser. No. 252,026, filed Jan. 17, 1963, and now abandoned.

This invention relates to novel metal-containing dyestuffs, a method of producing same and a dyeing process utilizing said dyestuffs. More particularly, the invention relates to novel cationic metal-containing dyestuffs which differ substantially in various properties from the conventional metal-contaning dyestuffs, and a method of producing the same. T o be more particular, the invention relates to novel metal-containing dyestuffs useful for dyeing various fibers such as synthetic fibers, semi-synthetic fibers, regenerated cellulose fibers, natural fibers, mineral fibers and the like, any suitable mixtures or blends thereof, and their products (e.g. yarn, fabrics, clothings, etc.), examples of the above-mentioned fibers including those of polyester, polyamide, polyurea, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, polyacetate, polypropylene, polyoxymethylene, polyethylene, viscose, cuprammonium rayon, silk, wool, cotton, linen as well as leather and glass.

With certain exceptions, fibers carry negative surface charges in a dye bath, and in the case of the so-called difficultly dyeable synthetic fibers such as polyester and polypropylene fibers, this tendency is so pronounced that with most anionic dyestuffs, it is almost impossible to dye these fibers owing to static problems. Furthermore, the conventional cationic dyestuffs or non-ionic dispersion dyestuffs which are employed to overcome the aboveice mentioned difiiculties have disadvantages with respect to their fastness, particularly their wet color fastness, sublimation fastness, and resistance to dry cleaning.

In this connection, it is further to be understood that the development of mixtures or blends of synthetic and natural fibers has complicated dyeing procedures to such an extent that a plurality of processes have to be actually employed to dye such mixed fibers or products thereof utilizing many different types of dyestuffs in various combinations according to the mode of mixture and the variety of fibers used.

We have found that a novel water-soluble metalcontaining cationic dyestuff is obtained when (1) a dyestuff having COOH and OH groups in ortho-position with respect to one another in the molecule, or (2) a dyestuff having CHNOH and OH groups in orthoposition with respect to one another in the molecule, is reacted with a trivalent-chromium compound, a tetravalent-zirconium compound, or a trivalentor tetravalenttitanium compound in a suitable solvent, and that the dyestuffs thus obtained may advantageously be employed for satisfactorily dyeing various fibers and products such as mentioned before.

There have heretofore been known a number of metalcontaining dyestuffs which are typically exemplified by the following chemical structures:

In practicing the invention, the starting material dyestuffs exemplified below may be employed:

Examples of those belonging to the Group 1:

A O HO N=N -0H 0-41: r 0 H 0 o 0 0H HO OH -O O H 060 c o 0 H L CH 011' N2 k1 l 3 I 3 o o H o 0 ArN H o 0 c- -o= c 0 on /0 /C o [C1(6HgO)]+* .HzO 0 01 O=C l H 0 0o 0 0 0H H0 8 0: =0 o Cr/3 0: :0 H Q -o o o H l N IQY H0 S 1% u N I OH H 038 C 0 0H It is apparent from the above structural formulas that l the conventional metal-containing dyestuffs are charac- 0H terized by being anionic and not cationic. C O o H The one and only known cationic metal-containing dyestutf is of the following type: O C o1r o Gr+ 0 While this type of dyestufi may be synthesized by heating an alcoholic solution of o-hydroxybenzene-azo-fi- G 0 0H naphthol together with chromium chloride, it is so unstable against heating in an aqueous solution that precipitation occurs. Therefore, this substance is not satisfactory for use as a dyestuif.

The dyestuffs of the invention are entirely different from the conventional metal-containing dyest-ufis in that 0 they are water-soluble, cationic and stable.

It is noteworthy that the compounds which are the starting materials to be used in the manufacture of the (B0011 dyestuffs of the invention, have never been used as materials for the conventional metal-containing dyestuffs, 5

and that the synthesis of the metal-containing dyesuffs according to this invention is essentially conducted in a non-aqueous solvent in sharp contrast to the conventional 110 process where water is used as the solvent. It is presum- AM W ably because of the use of these special starting materials COOH 09113 and of the novel, unique manufacturing conditions that the dyestuff of the invention produced thereunder pos- (30011 sesses the novel, unique characteristics which have hereinbefore been described and will more fully be explained and discussed hereinafter.

Examples of those belongin g to Group 2:

(3H (IJHN OH 1 1' (orange yellow) CHNOH C N=N 4H I l 02 (yellow) ooH3 CHN OH --N=N OH 31 (yellow) ('31 ([JHN 0H Q O (ye CHNOH (5 Fa (yellow) CHNOH CHNOH CHNOH 00113 OCH; ("JHNOH HO =NON=NOOH (yellow brown) The above-mentioned starting materials may be employed in the form of water-soluble metallic salts such as sodium salts, potassium salts, etc.

The metal compounds which are used in the synthesis of the dyestuffs of the invention by reacting with the aforementioned starting material dyestuffs are preferably compounds of trivalent or tetravalent chromium, titanium, or zirconium which would show acidity, such compounds being exemplified by titanium trichloride, titaniurn tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride, chromium formate, etc. Among those salts mentioned above, green crystals of chromium chloride are particularly preferred.

The basicity of the aforementioned metal compounds has to be lower than 50 percent, and preferably lower than 33.3 percent.

The reaction should be conducted in an acidic condition or at a pH below 4 (preferably below 2). Most of the above metal compounds when dissolved in a solvent exhibit a pH below 4. If necessary, however, a suitable acid may be added to the solution to adjust its pH to a prefenable one.

The amount of these metal compounds may vary depending on the particular chemical structure of the starting material dyestufl employed. Generally, the use of the metal compound is an amount within the range of 1 to 4 moles per mole of the starting material is most satisfactory in view of the quality of the resulting dyestuff as well as from economic considerations. It should be understood, however, that the use of more than 4 moles of said compound will not adversely affect the yield and quality of the final product.

Functional radical: Chromium (in mole per one functional radical) (1) -COOH and -OH in o-position with respect to one another 2 (2) CHNOH and --OH in o-position with respect to one another 2 When a chromium compound is employed in an amount less than the number of moles given in the table, the resulting dyestuifs Will be unstable and, in many cases, insoluble in water. The use of an excess of the metal will not produce objectionable results but, rather, may serve to accelerate the reaction. However, the practical limitation is that at best up to 4 moles of such metal per each functional group may be employed.

The solvent to be employed in the reaction of the invention has to satisfy the following requirements: (a) It should be capable of dissolving both the starting material or dye and metal compound, (b) it should not exhibit alkalinity, and (c) it has to be at least partially miscible with :water. While a number of solvents satisfy such requirements, the most commonly available of such solvents include, for example, alcohols, glycols and ketones, and, more particularly, methanol, ethanol, isopropanol, npropanol, ethylene glycol, polyethylene and the like. The organic solvent utilized is inert With respect to the starting material or dye and metal compound. Although, as a rule, water is not allowed to be present in the organic solvent at the commencement of the reaction, it may some times be advantageous that the solvent contains a small amount, e.g. up to 20% (based on solvent) of water in order to increase the basicity of the metal compound used and to enable the reaction to proceed more readily. Particularly, in many instances, Water of crystallization contained essentially in the met-a1 compound serves to accelerate the reaction of the invention.

The reaction time and temperature should vary according to the particular starting material dyestutf and, also, of metal compound, although, in many instances, the temperature range of 50 C. to 150 C., and, more commonly, up to C. will be satisfactory. In most cases the reaction is completed within about one hour.

The dyestufi's manufactured by the process described hereinbefore exhibit cationic property in the reaction system and also in water, with the number of metal atoms combined to one molecule of the dyestulf being from 1 to 4.

The solids which remain after the solvent is distilled off subsequent to the reaction may be put to use as such. Since the optimum molar ratios of the starting material dyestuff to the metal compound are as described above, and there would remain none unreacted so long as such ratios are strictly adhered to, the solution resulting from the reaction can be directly used for dyeing purposes without isolating the product dyestufi therefrom. Furthermore, some products (some of those dyestuffs which are obtained when titanium or zirconium is employed), once the solvent is completely distilled off, will not dissolve themselves completely in water. If such is the case, it will then be more advantageous to allow a part of the solvent to remain after distillation and put the product to use as a pasty dyestulf. While what might be obtained as by-products, in many instances, would be a trace amount of water or hydrochloric acid, neither of them would cause trouble in the actual use of the product dyestuffs, Where the functional group is COOH, and if a material containing COONa is employed in such case, NaCl will be formed as a by-product, which, however, may be easily removed by filtration before the solvent is distilled off.

Hereinafter will be set forth an explanation about the dyeing process utilizing the novel cationic dyestuffs of the invention. While the pH of adyestuff solution varies according to the type of the metal compound employed, it will show, for instance, a pH value ranging from 1 to 4.5 in water where crystalline chromium chloride is employed as the metal compound. In this instance, it is presumed that the cationic surface activity of the dyestuff overcomes the highly negative charge on the surface of fibers, thereby sufficiently penetrating into the fibers, where the dye is fixed onto the fibers through coordination bond, covalent bond, condensation, or/and insolubilization.

The dyestuffs of the invention may be applied to substrates in any conventional manner, i.e. by dipping, padding, coating, printing and the like. The substrates dyeable with the dyestuffs of the invention include, for instance, all the conventional easy-to-dye fibers, polyester fibers which are generally considered difficulty dyeable, and even fibers of polypropylene which has no active sites. In all cases, the said fibers are dyed vivid, fast colors. Moreover, except glass, most substrates can be successfully dyed with the dyestuff of this invention at a temperature below 100 C., and this fact is particularly beneficial when fibers vulnerable to heat, e.g. polypropylene, are to be dyed. It is to be understood, however, that no substantial trouble will be encountered if fibers are treated at a temperature beyond 100 C. in the dyeing treatment. On the other hand, in the case of cellulosic fibers and silk, satisfactory results may be obtained even when such fibers are dyed in the neighborhood of room temperature, and particularly with silk, this is quite beneficial in so far as it helps silk retain its unique hand. As regards glass it is preferably dyed in the neighborhood of 140 C., under dry conditions.

Among the dyestuffs of the invention are those which, after having been adsorbed on fibrous substrates, are improved in the fixation and/or wet colorfastness upon treatment with an acid binding agent or subsequent heattreatment. However, these treatments are not always nee-- essary for all the dyestuffs of the invention. Preferred examples of the acid binding agent include caustic alkali, alkali metal salts of, for example, carbonic acid, silicic acid, acetic acid, phosphoric acid, etc., and those alkalis (e.g. bicarbonates) which yield said alkali metal salts when heated. The inclusion of electrolytes such as sodium sulfate, sodium chloride and the like in an aqueous solution of the acid binding agent does not adversely affect the result of dyeing.

It should be appreciated that many of the novel dyestuffs of the invention may be employed in a single dyeing bath for dyeing various combination fabrics such as those containing natural or regenerated cellulose fibers on one hand and synthetic fibers on the other.

There are, of course, more or less variations in dyeing properties among the novel cationic dyestuffs according to the chemical structures of the respective starting materials, and, therefore, all the dyestuffs of the invention may not be expected to possess the same dyeing properties with respect to all textile fibers. However, it has been found that in a number of instances, by selecting suitable conditions, many kinds of combination or blended fabrics can be dyed in a single dyeing bath, and that, as will hereinafter be described in further detail, particularly satisfactory results may be attained in printing.

The printing process of the invention comprises printing a fabric with a printing paste containing one of the dyestuffs of the invention, drying the printed fabric, subjecting the same, then, to heating or steaming at a temperature around 100 C. or, if required, at a temperature higher than 100 C. but not exceeding 240 C., and, if required, reacting the fabric with an acid binding agent in an aqueous medium, it being understood that the lastmentioned treatment may be conducted either before or after said heat treatment.

The printing paste may contain usual assistant agents such as alcohol and glycol and/or organic acid such as acetic acid. As regards the thickening agent, locust bean Example 1 In 2000 parts of isopropanol was dissolved 50 parts of a starting material dyestuif having the following formula:

(13113 I HO "O HOOC C k/ COOH 1 To the resulting solution was added 53 parts of crystalline chromium chloride (27.3% basicity) and the mixture was boiled. As the reaction proceeded the mixture showed a change in color from orange red to blue. At the end of 3 hours, the solvent was distilled off, whereupon 99 parts of a dark violet dyestuff having a metallic luster was obtained. This dyestuff developed a blue color upon dissolution in water and had a maximum absorption at 585 my. A 0.1% solution of the dyestuff was passed columnwise over ion exchange resins. The results, as tabulated below, showed that the dyestuff obtained above was cationic.

Solvent;

Methanol Water Penetrating power:

Original dye solution 51.0 34. 9 After passage through anion exchange resin 51. 4 40. 8 After passage through cation exchange resin. 97. 1 99. 0

Wavelength: 585 m Similar results were obtained when acetone or ethylene glycol was used as the reaction solvent. About the same results were also obtained when 1800 parts of methanol and 200 parts of water were employed as a mixed solvent.

Example 2 T o a solution of 34.6 parts of a substance having the following formula:

Example N 0. Starting material dyestufi Type of Shade of dye Metal solution a HOGN=NO0H Cr Yellow.

I H O O {I} C O O H HI) C O 0 H 4- -N= Cr Red.

O OH 5 ON=N8O H Cr Yellowish brown.

C O OH 6 O2NN=N 011 Or Yellow.

7 N=NC OH Cr Do.

I C O O H 8 HO N=NONOa Cr Maroon.

I v C 50H:

E3 0 OH 9 or w O -C -C or I E O O H C O O H or I (I) O OH C O OH O ll 12 C O O H Or Green. "O l C O O H (in 13 HON=NOOH Ti Yellow.

Example 14 To a solution of 34.6 parts of a substance having the following formula:

in 1800 parts of ethanol was added 53.3 parts of crystalline chromium chloride (3.7% basicity), and the mixture was boiled for 7 hours. The insoluble by-prod-ucts such as sodium chloride were then filtered oil and the solvent distilled off, whereupon 81 parts of a glossy black violet To a solution of 6.9 parts (1/20 mole) of salicylaldoxime and 7.8 parts (3/40 mole) of sodium carbonic anhydride in 350 parts of water was added I/ 20 mole of diazotized S-nitro-o-toluidene to effect coupling, which yielded 14.1 parts of a yellow substance. After the product was purified with water and, then, methanol, and 2 parts of the purified product was dissolved in 50 parts of n-propan01, 'to which 4 parts of crystalline chromium chloride a Dyeing Examplel This example shows dyeing of polyoxymethylene and polypropylene fibers. U V

The said fibers were immersed in a bath containing a solution of 0.2 part of each of the cationic dyestuffs manufactured by metal-complexing the following starting material dyestufls respectively. The bath temperature was increased to and maintained at 90? C. for 1 hour, at the end of which time the fibers were washed with water and,

10 then, soaped. The dyed fibers were found excellent in wet Example Starting material dyestufi Type of Shade of dye No. metal solution (IJHN OH 16 -N=N H Cr Yellow.

(Ill CHN 0 H fiJHN OH CHN OH CHN OH CHNOH OCH; ([)CH3 CH; CHNOH 21 ON: OH

Yellowish brown.

0 EN 0 H O H Or Do.

Zr Yellow.

color fastness, fastness to sublimation, and resistance to dry cleaning.

Dye No.

Starting material dyestufi Type of Shade of dyed metal material CH3 CH3 HO 0 1 .NaOOC COONa C! Blue.

13 Dyeing Example 2 This example illustrates dyeing of mixed cotton-polypropylene fabrics.

In a bath containing a solution of 0.1 part of each of the following dyestuffs in 300 parts of water were 5 immersed parts of a sample of the above-mentioned refined, bleached and mercerized mixed fabric (:50). The bath temperature was held at C. for 1 hour, at the end of which time the fabric was washed with water and, then, soaped. The fabric was uniformly dyed, and 10 was found excellent in wet color-fastness and colorfastness to sublimation, dry cleaning and friction.

A dyeing paste of the following composition was employed:

Parts Dyestuff of the invention (see below) 3 Polyethylene glycol 3 Acetic acid (50%) 2 Water 42 Inda-rca A./BV (8% aqueous solution) 50 The paste was applied to each of the above-mentioned previously refined mix-spun fiber fabrics on a screen print- Dye No. Starting material dyestufi Tglgteapf shaggtcigjyed CH (EH;

1 HO- 0 Cr Blue.

0 0 C- C O ONa COOH 2 OQN-Q- =N OH Cr Yellow.

CH (IJHNOH 3 N OOH Cr Orange yellow.

Dyeing Example 3 This example illustrates printing of fabrics of the following mix-spun fibers. (1) Mix-spun fiber (2) Mix-spun fiber broadcloth polyester-cotton (65:35). (3) Mix-spun fiber cloth copolymer (60% vinyl chloride, 40% acrylonitrile)-cotton.

broadcloth polypropylene-cotton 40 ing machine and, after drying, the fabric was padded with an aqueous solution containing 0.2% of soda ash and 20% of crystalline Glaubers salt at room temperature, and then steamed at 100 C. for 5 minutes, at the end of which time the fabric was washed with water, subjected to soaping with an aqueous solution containing 0.3% of soap and 0.2% of soda ash at 60 C. for 10 minutes, washed with hot water, and washed again with water. The fabrics were found to have been colored uniformly and to be excellent in wet color-fastness and fastness to both sublimation and dry cleaning.

15 Dyeing Example 4 Dye No. Starting material dyestufi Type of Shade of colored material Type metal HN O H Starting material dyestufi 0H Cr Yellow.

Shade of dyed metal material NaOOC COONa Green.

Dyeing Example 5 This example illustrates dyeing of wool, silk, nylon and cotton.

In a dyeing bath containing a solution of 0.3 part of each of the following dyestuffs in 500 parts of water was immersed parts of each of the above-mentioned fibers. The bath temperature was increased to and maintained at Having thus disclosed the invention, what is claimed is:

1. A water-soluble thermostable cationic complex metal compound of a member selected from the group consisting of the dyes of the formulae 80 C. for 1 hour. Cellulosic fibers and silk could be dyed (3H3 CHN satisfactorily even at room temperature and the dyed substrates had an excellent color fastness. An alcoholic solu- OH tion of such a dyestutf could also be utilized with equal success. 40 N01 Dye No. Startingmaterial dyestufi Type Shade of of dyed metal substrate OCH: OCH:

1 r I CHNOH ('lHNOH 2.. HOON=N H Cr Yellow. I c0 OH 00 OH a H0QN=NQ0H Tl Yellow.

GOOH coon Dyeing Example 6 CHNOH This example illustrates dyeing of animal hides and I skins. N=N- 3-0H In a solution of 1 part of each of the following dyestufis in 100 parts of methanol was immersed a sample of N0: tanned bovin hide at room temperature for 2 minutes, at 00H; (|JHNOH the end of which time the hide was dried in air. The dyed hide had a satisfactory fastness to friction and solvents. N=N OH It was found that tanned hides could also be spray-colored. 1

Type Shade of or CHNOH Dye No. Starting material dyestufi of colored metal material on CH; OH:

I I CHNOH 1 HO :0 Cr Blue.

N=N OH H000 0/ COOH 7 Fa Cl -01 CHNOH (IJHNOH OCH; OCH: CHNOH the metal being selected from the group consisting of trivalent chromium, tetravalent zirconium, trivalent titanium and tetravalent titanium, obtained by reacting the corresponding member of the said group, as starting dye, with from 1 to 4 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium formate at a pH of below 4 at a temperature of 50 to 150 C. in an inert organic solvent which (a) is a solvent for the starting dye and for the resulting metal-containing compounds, (b) exhibits no alkalinity, and (c) is at least partially miscible with water.

2. The water-soluble thermostable cationic complex metal compound of the dye of the formula (EH3 CHNOH obtained by reacting 2 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium formate at a pH of about 2 at a temperature of 50 to 150 C, in an inert organic solvent which (a) is a solvent for the starting dye and for the resulting metal-containing compound, (b) exhibits no alkalinity, and (c) is at least partially miscible with water.

3. The water-soluble thermostable cationic complex metal compound of the dye of the formula l loz obtained by reacting 2 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium CHNOH CHNOH obtained by reacting 2 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium formate at a pH of about 2 at a temperature of to 150 C. in an inert organic solvent which (a) is a solvent for the starting dye and for the resulting metal-containing compound, (b) exhibits no alkalinity, and (c) is at least partially miscible with water.

5. The water-soluble thermostable cationic complex metal compound of the dye of the formula 01 CHNOH obtained by reacting 2 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium formate at a pH of about 2 at a temperature of 50 to 150 C. in an inert organic solvent which (a) is a solvent for the starting dye and for the resulting metal-containing compound, (b) exhibits no alkalinity, and (c) is at least partially miscible with water.

6. The water-soluble thermostable cationic complex metal compound of the dye of the formula CHNOH QN=NGOH obtained by reacting 2 moles, per mole of starting dye, of

CHNOH OCH; CHNOH CHNOH obtained by reacting 2 moles, per mole of starting dye, of a compound having a basicity lower than 33.3 percent and being selected from the group consisting of titanium trichloride, titanium tetrachloride, zirconium oxychloride, chromium chloride, chromium fluoride and chromium formate at a pH of about 2 at a temperature of 50 to 15 0 C. in an inert organic solvent which (a) is a solvent for the starting dye and for the resulting metal-containing compound, (b) exhibits no alkalinity, and (c) is at least partially miscible with water.

8. The water-soluble thermostable cationic complex metal compound of the dye of the formula 0 CH3 OGHa CHNOH 191 20 obtin'edhy reacting 2 moles, per mole of s tart ing dye, of 2,492,959 1/1950 Blumenthal 260l48 XR a-'eo1iipo 1'fid having 'a ba'sicity lower than 33.3 percent and 2,626,255 1/ 1953 Blumenthal 260-148 XR being selected from the group consisting of titani'um tri- 2,690,438 9/1954 Kracker 260149 XR chloride, titanium tetrachloride, zirconium oxychloride, 2,726,238 12/1955 Morschel'et a1. 260149 XR chrornium chloride, chromium fluoride and chromium 5 1 fol-mate et a pH of about 2 at a temperature of 50 to FOREIGN PATENTS 150 C. in an inert organic solventwhich (a) is a solvent 58591.41 710/1959, Canadafor the starting dye and for the resulting metal-containing .4 5 8/1937 Great Britain compound, (b) exhibits no alkalinity, and (c) is'at'least 1,122,461 5/ 1956 France- P31111111}! miscible with water. 10 OTHER REFERENCES References Cited Brass et 81.: C.A., vol 33, pp. 8187-8188 1939).

U 1:11.: C.A., 1. 36, 807 1942. UNITED STATES PATENTS Emma e p 2,120,799 6/1938 Crossley et 1. 260-147 FLOYD D; HIGEL, Primary Examiner- 2,421,31s 5/1947 Cerson 260-447 

